Balance indicator for airplanes



i uana if, J H, GERDES 1,881,692

BALANCE INDICATOR FOR AIRPLANES Filed Feb. 14, 1928 Patented June 7, 1932 CARL J QHN HENRY GERDIES,,OF HASBROUGK; HEIGHTS; NEW JERSEY:

BALANCE INDICATOR FOR AIRPLANFES:

Application filedEebruary; 14, 1928: SeriaPNoa 254279.

'Bhisdnvention; relatesto. devices for: in: dicating -whether an'iairpl'ane is; on an even: keelior whethenit; is downwardly; inclined: on laterally. inclined; and the object of the-ins ventionj is to obviate the. dangerto a. pilot:

when flying throughlfog and: ClQllClS:Wl1BI6 it isimpOssible because;of the factlthatithe;

pilot cannot see the, horizon, .for: him; to note,

whether-the: airplane is: on; an evenlieel" and,

lo' is therefore; unable to a correct the direction movement of the planeuntilztoolate;

A ifurthervobjectisi to provide. a1device of this: character; which. includes: a; pendulum supporteda in: front ot the pilot; .the inclina- 15==tion of: the pendulum; to right: orleft? or forwardi or rearward: of an. indicating line showing the direction; of inclination of: the. airplane; and". the & degree of this inclinatiom andialsoindicatingrwhetlier OI 'llOTiE tllfi'tPllOt;

zmhasbrought the ship back; to proper-flying:

position-or the: positiondesired by him:v

A u still further obj eat is: to, provide: means for-,rotating-the. pendulumiatzaa'elatively higlt rate of; speedl in .themanner 1 of gyroscope i-o' so' that the rotation of thependulnmzwillzi tendxto; resist; lateral movementithereof; thus preventing: the device; from: being too sens sitivezandiswingingzunduly.

inventionzis illustratecbin the aceom-oempany-ing-drawing, .wlier.ein v Figure 1' is; a=. diagrammatic. View: of. my. device; mounted: in: connection with an! airplane; it being; understood; of: course; that the: device: itself: need not: bear: the: propor;--

tions-that it: does in the; illustration EigureaQ; is anelevation: partly in; sectioni of my,-indicatori;

Figure 3.- is l a: section on the: line: 3ff3's of; Fig-2:;

Eigure; i; is a section.- through the gimbah joint :which isupportsthe pendulumg:

Eigure: 5 is; a; top plan; view of? the: bowl! Within which;v the pendulum; swings.

Referring toathissdrawinggiitw will be seen; 45? that; the indicator comprises-ea: horizontally. disposed? windwheel casing; designated:

10. Thisoasingq isecircularin; formiand is" formed f a.- lower section: 111i andl aitop 12, tllG-zlOWQIT section haying, atdownwardlyieare 593 tending: hub: 131 supporteda uponzthewcoweling ofi'the fuselage by means offa bolt-14. tending tangentially from the casing is an outwardly flaring air inlet pipe or A reoeiven 15, and? also extending; tangentially from the casing 10 isan outlet 16.

Mounted within the casing and rotating-- with a spindlelT is-a windw-heel 18*; which may be of any; desired fornn but which" is illustrated as being; formed on its-periphery: with the pooketspr: blades-19. As'shown; this Windwheell is keyed to: the spindle 17 and is held in placeby IHGaHS OfthG washer 20an'discrew 21*. Extending:downward from the hub 18 is tubular casing QQ through whiehlthe reduced lowen portion ofi'tlie spin dle 17 extends The-spindle is supported withinthe tube 22-by ball bea-rings or otheranti=friction bearing-$ 23 and the- Wind'wheel is supported upon ball bearings =24", the balls of these bearings resting upon the lowerrace-- ways '25 and bearing against the upper raceway;26 which is oarried by the Wheel IS; Any other suitable means-forsupporting the spin dle may be used. 7

The lower end:' of he spindle- 17 carries pinnedi upon :it" an enlarged cylin'drical' memben-Qi'i pinned to-the spindle at 28 'and for-m ing part thereofl The lower end? of this= member 27' carries the transverselyextend ing shaft 29 which hasbearing/at'its endsin theseringsibeing held tog'ether by sorews-fiQ-J Mounted in be arings between these 1 rings 1 30 Y and 31 and 'on an .axisat right anglesto'tlieaxis of the shaft 29xare-the gudgeons or short shafts =33," and swingingly engaged with the outer endsof these gud'geons is r a yoke 34d which depends therefromand supports a-= pendulum comprising-'- the pendulum I rod 35;-

- whose. upper 'end is disposed within a-:socket 36: carried by the yoke: 254 and apendulum bob 37 carried upon the lower end of the pendulum rodi This'biob is quite heavyiandi the lowerendiofi'tlie bob has thefbrm'aof'i' an invertediconer The rodi35l may be held" in. place in .thezbob by: means: ofr assets screw-. on pin 38.

ItiwilLbe-seenzthatwbyrthiszconstructionitlie V pendulum zoanavibrateor swihgrimtwo-planea atzright angles to each other or in a plurality of planes radial to the axial center of the shaft 17 The pendulum is in elfect connected to the spindle or shaft 17 by a universal joint which permits the easy swinging of the pendulum in any direction but which will at the same time transmit rotatory movement to the pendulum.

Disposed below the pendulum is a relatively shallow bowl-shaped dial 39 having a curvature parallel to the path of movement of the lowest portion of the pendulum in any direction and having an upstanding rim 40 which limits the movement of the pendulum. This dial, as shown in Figure 5, has diametrically extending indicating lines 11 and the interior. of the dial also is: formed with a plurality of circles 42 concentric, of course, to the center of the dial and intersecting the lines 41. It will be understood that degree marks might be applied in connection with these lines 41 or the circles so asto indicate the degree of inclination of the dial with respect tothe vertical pendulum and the direction which said angle of inclination takes.

-' Thependulum and dial will thus indicate the extent to which the airplane is being tilted either in a forward or rear direction or in a lateral direction. Two powers, it will be seen, are working together to resist movement of the pendulum, namely the weight of the pendulum bob 3? and the resistance or inertia due to the high speed of rotation of the pendulum bob 3? which operates in the well known manner to resist movement of the bob from the position it occupies at any one time to the other position. Obviously, the longer the pendulum, the greater the weight of the pendulum bob and the steadier will be the movement of the pendulum.

The rim 4:2 limits the movement of the pendulum so that the pendulum will not swing out or ofl of the dial when the aviator is doing stunts or flying upsidedown or thelike. It will be seen that this indicator will indicate to a 1 pilot when flying through the dark or through and whether it is nosing down or nosing up and the degree of the angle to the horizontal made by the ship. At the same time, the high rotational speed given to the pendulum bob and rod and the weight of the pendulum bob and rod will tend to resist slight vibrations and oscillations of the pendulum bob which would be confusing.

While I have illustrated a particular form of my invention, 1 do not wish to be limited thereto as it might be embodied in other forms without departing from the spirit thereof as defined in the appended claims.

I claim 1. An inclinometer for use with airplanes comprising a vertically rotatable spindle, a-

pendulum connected to the lower end of the spindle for rotation therewith around the longitudinal axis of the pendulum but adapted toswing in a plurality of planes radial to the axis of the spindle, the pendulum terminating in a heavy bob, means for rotating the spindle at a high rate of speed and a dial fixed with relation to the pendulum and over which the pendulum freely moves.

2. An inclinometer for use with airplanes comprising a spindle, a pendulum connected to the lower end of the spindle for rotation therewith but adapted to swing in a plurality of planes radial to the axis of the spindle, the pendulum having a heavy bob, a windwheel mounted upon the spindle and having a casing, and means for admitting air to said casing to drive the-windwheel at a high rate of speed including an outwardly flaring receiver opening into the casing at a tangent thereto, the casing having an outlet.

3. An inclinometer for airplanes compri ing a circular casing having a tangential air funnel opening thereintoand having an air outlet, a spindle extending into the casing and carrying a windwheel formed with peripheral blades against which the wind from said funnel strikes, an anti-friction support for the spindle holding the spindle at right angles to the windwheel, and a pendulum operatively connected to the lower end of the spindle for rotation therewith, said pendulum being adapted to swing in a plurality of planes with relation to the spindle, and a dial over which said pendulum moves. J

4. An inclinometer for airplanes comprising a casinghaving a hub and a tubular extension therefrom, the casing having a fun nel-shaped air inlet and having an outlet, a windwheel mounted within the casing and having peripheral blades, a spindle carried by the wheel and extending downward through the hub and tubularv extension, antifriction bearings for said spindle, a pendulum having a bob at its lower end and a gimbal ring at its upper end disposed in a plane at right angles to the pendulum, a member mounted on the lower end ofthe spindle for rotative movement around an axis at right angles to the longitudinal axis of the spindle,

said member carrying a bearing mounted on dulum may swing in a plurality of planes radial to the central 'axis of the spindle.

5. Aninclinometer for'airplanes including a rotative member, a spindle carried thereby,

a pendulum operatively connected to the spindle to rotate therewith but mounted for swinging movement in a plurality of planes radial to the spindle, a bob carried by the lower end of the pendulum, an upwardly dished dial over which the bob moves, the

dial having a rim limiting the movement of the bob and preventing the bob from swinging out of the dial, the dial having indicating marks extending diametrically across the dial, and a series of circles concentric to the dial.

6. An inclinometer for airplanes including an oscillatablependulum,and means for rotating the pendulum at a high speed around the longitudinal axis of the pendulum, said means including an air operated driving element operatively connected to the pendulum to rotate therewith, and means to direct a current of air against said element and a dial over which the lower extremity of the pendulum moves freely in all directions, said dial having graduations showing the extent and direction of movement of the pendulum.

7. An inclinometer for use with airplanes comprising a spindle rotatable around a vertical axis, a pendulum connected to the lower end of the spindle for rotation therewith but adapted to swing in a plurality of planes radial to the axis of the spindle, the pendulum terminating in a heavy bob, a wind wheel mounted upon the spindle for rotation therewith, and having a casing provided with a wind discharge opening, means for receiving air currents directed against the plane when in motion and directing said air currents into said casing to drive the wind wheel at a high rate of speed, and a dial coacting with the pendulum and over which the pendulum free- 11y; inoves in any direction diametric to the c 1a In testimony whereof I hereunto aifix my signature.

CARL JOHN HENRY GERDES. 

